Neurological symptoms of COVID-19 can last months

Among 27 patients who had such symptoms weeks after recovering from COVID-19, only nine reported complete resolution six months after joining the study, researchers reported in Annals of Clinical and Translational Neurology. The remaining 18 still had nervous system abnormalities - most often, impaired memory and trouble concentrating - although generally the symptoms had become less severe.

"Some of these participants are high-level professionals who we'd expect to score above average on cognitive assessments, but months after having COVID-19, they're still scoring abnormally," Dr. Jennifer Graves of UC San Diego Health said in a statement.

Most study participants had mild or moderate COVID-19. Graves said she suspects the neurological symptoms are caused by an immune response to the virus.

In four patients, her team saw a previously unidentified set of symptoms that included cognitive deficits, tremor and difficulty balancing. "These are folks who had no neurological problems before COVID-19, and now they have an incoordination of their body and possible incoordination of their thoughts," said Graves. "We did not expect this."